PowerPlant

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kitaraopetusta
Posts: 2
Joined: Tue Oct 16, 2012 4:31 pm

PowerPlant

Post by kitaraopetusta »

Hello!

I am building four ez1290 preamps on Martin A´s Boards.
I red that four preamps might suck as much as 2 Amperes.
Martin recommends one JLM´s AC/DC kit for every two ez1290 preamps.

Could I Just use one Powerplant kit???
Is it cabable to provide enough of power and will it be stable???

Or should I just buy two acdc kits?
What do you recommend???
Thank you very much already!

T:Veli

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Joe Malone
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Re: PowerPlant

Post by Joe Malone »

kitaraopetusta wrote:Hello!

I am building four ez1290 preamps on Martin A´s Boards.
OK
I red that four preamps might suck as much as 2 Amperes.
A 1290 with the output amp trim pot set correctly draws always 110mA to 120mA each as it is Class A.
Martin recommends one JLM´s AC/DC kit for every two ez1290 preamps.
One AC/DC kit with a good heatsink can run 8 x 1290 modules fine.
Could I Just use one Powerplant kit???
Yes the New Power Plant was designed exactly for running 4 x 1290 mic pres with phantom power (480mA). The Power Plant can deliver 800mA so can actually power 6 x 1290 with some spare but I recommend 4 x 1290 to leave some headroom for any future 1290 faults.
Is it capable to provide enough of power and will it be stable???
Yes. Main thing with Newly built 1290 kit is to power them up one at a time and adjust the output amp trim pot for 1.4v across the 12R 1W resistor so they draw the correct current before connecting all modules to the power supply. This also helps if one newly built module has a fault in it.
Or should I just buy two acdc kits?
No. But even if you were going to use AC/DC kit you would only need one for 4 x 1290.
What do you recommend???
One Power plant kit. We power our new 1290x4 rack with one Power Plant in a small external diecast box and it only runs warm to the touch. See below.

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Joe :-)
JLM Audio
Capturing Audio without Injury

kitaraopetusta
Posts: 2
Joined: Tue Oct 16, 2012 4:31 pm

Re: PowerPlant

Post by kitaraopetusta »

Thank you for quick and definitive answer!!
I got my kit and almost finished it already.

One think pumped into my mind though,
It seems weird NOT to have any heat sink in 317.

Are you sure the regulator will not fry?

Thanks very much!

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Joe Malone
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Re: PowerPlant

Post by Joe Malone »

kitaraopetusta wrote:Thank you for quick and definitive answer!!
I got my kit and almost finished it already.

One think pumped into my mind though,
It seems weird NOT to have any heat sink in 317.

Are you sure the regulator will not fry?

Thanks very much!
The 2 x LM317 reg under the power plant PCB need to be tightened down to a metal case or heatsink. The screw into the power transformer will clamp the regs in there silicon tube down to the metal case or heatsink.
Joe :-)
JLM Audio
Capturing Audio without Injury

Uncledano
Posts: 1
Joined: Thu Jan 10, 2013 8:44 am

Re: PowerPlant

Post by Uncledano »

Joe:

I am new at this…although I have assembled dozens of Go-Betweens. Where can I find build instructions for the Power Plant? I am also a little confused about the AC power in….what is "VS SYNC"? Is that ground?

Dan
Uncledano

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Joined: Thu Jan 10, 2013 8:44 am

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Joe Malone
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Re: PowerPlant

Post by Joe Malone »

Uncledano wrote:Joe:

I am new at this…although I have assembled dozens of Go-Betweens. Where can I find build instructions for the Power Plant? I am also a little confused about the AC power in….what is "VS SYNC"? Is that ground?

Dan
Uncledano

Posts: 1
Joined: Thu Jan 10, 2013 8:44 am
Power Plant Build thread now at link below. Free free to ask any questions there as you build and I will put up more info there as needed.

http://www.jlmaudio.com/forum/viewtopic.php?f=2&t=231
Joe :-)
JLM Audio
Capturing Audio without Injury

XAXAU
Posts: 5
Joined: Thu Feb 19, 2015 6:04 am

Re: PowerPlant

Post by XAXAU »

I assume the diecast alu box is a Hammond right? I´m trying to figure out which one it is but I´m not sure. Do you remember which one it is?

Planning on putting it inside a 2U box with 2x EZ1290´s so it has to fit! :)

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Joe Malone
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Re: PowerPlant

Post by Joe Malone »

XAXAU wrote:I assume the diecast alu box is a Hammond right? I´m trying to figure out which one it is but I´m not sure. Do you remember which one it is?

Planning on putting it inside a 2U box with 2x EZ1290´s so it has to fit! :)
The aluminium box does not shield the power transformer flux so will not stop it putting hum into audio input transformers so must be outside of the rack case preferably some distance away.

If you want to mount the PowerPlant in the rack case mount it on the side of the rack at the back and make a 2 to 3mm STEEL U channel the full depth of the case to make a full steel case around the power supply.

Have all the mains wiring and power switch in the U channel section and one hole with rubber grommet for the 0v, 24v and 48v wiring to exit to the rest of the case.

Basically a full steel case around the power supply inside the rack case.
Joe :-)
JLM Audio
Capturing Audio without Injury

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